The eucalyptus grove atNatural Bridges State Beach—for four months out of the year, a clustering and resting place for butterflies—stands empty.

So too does the park’s visitor’s center and its parking lot, as if mourning the departure of this year’s monarch population, which recently fluttered away for the season.

Docent Abbey Pulman, dressed in the official brownish green California State Parks garb, looks up in surprise when I walk through the doors of the Natural Bridges visitor center. Not many people, apparently, wander into the gray, stout building when monarchs aren’t around.

These days, fewer of those winged insects are visiting Natural Bridges. The black-and-orange vortexes that greeted generations of field-tripping children and tourists are gone—in their place, a much smaller community of monarch butterflies barely clings to a few dying trees in the winter.

“We’ve had a significant butterfly decline in just the last three years I’ve been here,” Pulman says. “Over 50 percent.”

But the populations were in freefall even before that. Since 1997, monarchs’ overwintering population at Natural Bridges has dropped 97 percent. This year, a paltry 3,500 butterflies made Santa Cruz’s Natural Bridges their winter home, down from 130,000 two decades ago.

“Our grove is getting old,” Pulman says. “Trees are falling down, and the grove is not as protected. But threats come from man and nature.”

Beyond Natural Bridges, monarch butterfly populations have plummeted across the nation—around the whole continent, actually. Their overall numbers have fallen 78 percent since the mid-’90s.

For centuries, monarchs have dined almost entirely on a flowery plant called milkweed. Genetically modified crops and Monsanto’s Roundup herbicide have virtually wiped out milkweed on 165 million acres of prime monarch habitat and feeding grounds, an area about the size of Texas,according to the Center for Biological Diversity. This has led to monarch starvation on a mass scale, disrupting an annual migration that was previously one of the most spectacular in the world. Since 1997, milkweed prevalence has declined by 58 percent in Midwestern agricultural areas, while monarch populations there dropped 81 percent.

Extreme weather fueled by climate change poses an additional threat. Today’s entire monarch population would have been killed three times over by the single storm that raged in 2002. That event permanently disrupted migration routes, and destroyed a whopping 500 million butterflies.

If these trends continue and disrupt the monarchs’ migration paths, the butterflies will stop coming to Santa Cruz, which would spell trouble, Pulman explains. “They won’t survive if they don’t migrate,” she says slowly, looking me straight in eye. “They would all die.”

Groups all the way from Canada to Mexico are trying to prevent the monarch from literally disappearing off the face of the Earth. The butterflies need a very large population size to be resilient, says George Kimbrell, a senior attorney at the Center for Food Safety.

It’s absurd that monarchs are still not protected under the Endangered Species Act, says Kimbrell—and many scientists and environmentalists agree. The responsibility goes beyond national borders, and at a time when U.S. diplomatic relations with Mexico and Canada are poor, it appears the monarch’s fatemay depend on whether or not the three nations can come together with a shared plan.

“Working together with Canada and Mexico is vital. The U.S. leading the way is extremely important, and without ESA protection, monarchs will go extinct,” Kimbrell says.

After years of battling bureaucrats to try and protect the species, the Center for Biological Diversity, a nonprofit conservation organization, recently made some major progress. The center—whose officialmission is “saving life on Earth”—has been fighting the U.S. Fish and Wildlife Service. In late 2016, after numerous petitions and legal wranglings, it finally forced the department into action. The latest legal settlement requires Fish and Wildlife to decide on monarch protection by June 2019.

The center’s experts believe that the plummeting population of the monarch—along with other butterfly and bee species—threatens the well-being of humans, because our food security depends on the specialized ecological support that pollinators provide.

At this point, saving butterflies would likely require a massive amount of time and energy, even if the Fish and Wildlife Service decides to protect them in two years. (A big if, given that President Donald Trumptried to block similar protection for the rusty patched bumblebee on his first day in office.)

The Monarch Joint Venture (MJV) provides ground support for the Center for Biological Diversity in its ongoing battle. MJV is a partnership of federal and state agencies, non-governmental organizations and academic programs that work together to protect monarch migrations nationwide. The partnership of more than 60 organizations aims to add 1.6 billion stems of milkweed in the Eastern United States and conserve overwintering habitat through conservation, education and monitoring. “If people in every sector get involved in monarch conservation, we can make a difference and bring back the monarchs,” says MJV spokesperson Cora Lund Preston.

MJV has partnered with other entities like the U.S. Forest Service, Make Way for Monarchs, Journey North, Monarch Alert, the Environmental Defense Fund, the North American Butterfly Association, and the World Wildlife Fund.

Down in Mexico, one tiny butterfly-saving outfit called Alternare combats logging in the country’s butterfly preserve.

Alternare and its director, Lupita del Rio Pesado, have built a sustainable model that protects the forest and shares it with locals. Del Rio Pesado teaches farmers about alternatives to trees—like using adobe instead of wood, or switching to wood-saving stoves.

In Canada, organizations like the Butterflyway Project work on creating a complex of butterfly-friendly urban corridors, while the government debates whether or not monarchs should get protection as a Canadian endangered species. That decision is less than nine months away.

Abbey Pulman calls monarchs a “gateway bug,” and says that the monarchs’ decline is a harbinger of widespread environmental change. The significant monarch decline at Natural Bridges worries her and has her questioning the survival of another important species, human beings.

“The next generation will only hear about these things in stories,” says Pullman, “and that’s sad.”

Hugh, an intern at Good Times and Santacruz.com, recently finished his Journalism AA at Cabrillo College and now attends UCSC as a Sociology major with a focus on Global Information and SocialEnterprise Studies. If you need to get a hold of him, check 26th Avenue Beach

Monarch numbers are way down at Natural Bridges for political reasons: park management has refused to replant old eucalyptus trees that have gradually died or fell down during the past 20 years. Why refused? For political correctness reasons: eucalyptus trees are not native to California.